package codingforgreat.lchot150;

public class Lc070 {
    public int climbStairs(int n) {
        if(n == 0){
            return 1;
        }
        if(n < 0){
            return 0;
        }
        int[] dp = new int[n + 1];
        dp[0] = 1;
        dp[1] = 1;
        for(int i = 2;i <= n;i++){
            dp[i] = dp[i - 2] + dp[i - 1];
        }
        return dp[n];

    }
}
